Here is and an example:
Let say you have power sensitive component (like mixer (LO) or double...), and you like to measure conversion loss with exact power on device, however your device is on lossy fixture. Now does the port extension or de embedding can move the power reference plane by increasing the source power to overcome fixture loss?
regards,
mirek
With port extensions you can't move the source power reference plane, but with Fixturing (i.e 2-port fixture de-embedding) you can. the feature is called Fixturing Power Compensation and you can learn more about it here in the online help.